Brain Network Connectivity and Executive Function in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia

Attention and executive functioning in children and adolescents treated for high-risk acute lymphoblastic leukemia: A report from the Children's Oncology Group (COG)

OBJECTIVES

Survivors of childhood B-acute lymphoblastic leukemia (B-ALL) are at risk for difficulties with attention and executive functioning (EF) as a late effect of treatment. The present study aimed to identify treatment and demographic factors associated with risk for difficulties with EF in youth treated for high-risk B-ALL.

METHOD

Children and adolescents with B-ALL treated on Children's Oncology Group (COG) protocol AALL0232 were randomized to high-dose or escalating-dose methotrexate (MTX), and either dexamethasone or prednisone during the induction phase. Neuropsychological functioning was evaluated via protocol AALL06N1, including performance-based and parent-report measures, for 177 participants (57% female, 81% white; mean age at diagnosis = 8.4 years; SD = 5.0) 8-24 months following treatment completion.

RESULTS

Mean scores for all attention and EF measures were within the average range, with no significant differences as a function of MTX delivery or steroid treatment (all p > 0.05). In multivariable models, participants with US public insurance exhibited significantly greater parent-reported EF difficulties than those with US private or non-US insurance (p ≤ 0.05). Additionally, participants diagnosed under 10 years of age performed significantly more poorly on measures of attention (i.e., continuous performance task, p ≤ 0.05) and EF (i.e., verbal fluency and tower planning task, p ≤ 0.05).

CONCLUSIONS

For survivors of pediatric B-ALL, treatment-related factors were not associated with attention or EF outcomes. In contrast, outcomes varied by demographic characteristics, including age and insurance type, an indicator of economic hardship. Future research is needed to more directly assess the contribution of socioeconomic status on cognitive outcomes in survivors.

Impact of Propofol Exposure on Neurocognitive Outcomes in Children With High-Risk B ALL: A Children's Oncology Group Study

PURPOSE

Many children treated for ALL develop long-term neurocognitive impairments. Increased risk of these impairments is associated with treatment and demographic factors. Exposure to anesthesia is an additional possible risk factor. This study evaluated the impact of cumulative exposure to anesthesia on neurocognitive outcomes among a multicenter cohort of children with ALL.

METHODS

This study was embedded in AALL1131, a Children's Oncology Group phase III trial for patients with high-risk B-ALL. In consenting patients age 6-12 years, prospective uniform assessments of neurocognitive function were performed during and at 1 year after completion of therapy. Exposure to all episodes of anesthetic agents was abstracted. Multivariable linear regression models determined associations of cumulative anesthetic agents with the primary neurocognitive outcome reaction time/processing speed (age-normed) at 1 year off therapy, adjusting for baseline neurocognitive score, age, sex, race/ethnicity, insurance status (as a proxy for socioeconomic status), and leukemia risk group.

RESULTS

One hundred and forty-four children, 76 (52.8%) males, mean age of 9.1 (min-max, 6.0-12.0) years at diagnosis, underwent a median of 27 anesthetic episodes (min-max, 1-37). Almost all patients were exposed to propofol (140/144, 97.2%), with a mean cumulative dose of 112.3 mg/kg. One year after therapy, the proportion of children with impairment (Z-score ≤-1.5) was significantly higher compared with a normative sample. In covariate-adjusted multivariable analysis, cumulative exposure to propofol was associated with a 0.05 Z-score decrease in reaction time/processing speed per each 10 mg/kg propofol exposure (P = .03).

CONCLUSION

In a multicenter and uniformly treated cohort of children with B-ALL, cumulative exposure to propofol was an independent risk factor for impairment in reaction time/processing speed 1 year after therapy. Anesthesia exposure is a modifiable risk, and opportunities to minimize propofol use should be considered.

Characterization of brain development with neuroimaging in a female mouse model of chemotherapy treatment of acute lymphoblastic leukemia

Background

Survivors of pediatric acute lymphoblastic leukemia (ALL) exhibit abnormal neurocognitive outcomes that are possibly due to exposures to neurotoxic chemotherapy agents. This study aimed to determine the feasibility of characterizing long-term neuroanatomical changes with in vivo neuroimaging in a preclinical model of treatment for ALL.

Methods

Female mice (C57BL/6) were randomly assigned to a saline control group (n=10) or a treatment group (n=10) that received intrathecal methotrexate and oral dexamethasone (IT-MTX + DEX). Mice were subsequently scanned three times on a 7T MRI at ages 3, 6, and 12 months (T1, T2, and T3, respectively), which corresponds with human age-equivalents spanning early to late adulthood. Regional brain volumes were automatically segmented, and volume change between timepoints (i.e., T1 to T2; and T2 to T3) were compared between groups (i.e., saline vs. IT-MTX + DEX).

Results

Five mice in the IT-MTX + DEX group, and seven mice in the saline group completed all three scans. Between T1 and T2, volumetric change was significantly different between groups in total gray matter [estimate =2.06, 95% confidence interval (CI): 0.27-3.84], the cerebrum (estimate =1.62, 95% CI: 0.14-3.09), claustrum (estimate =0.06, 95% CI: 0.02-0.09), amygdala (estimate =0.16, 95% CI: 0.03-0.29), and striatum (estimate =0.18, 95% CI: 0.01-0.35), with the IT-MTX + DEX group exhibiting a more robust increase in volume than the saline-treated group. Between T2 and T3, group differences in structural brain development were evident for total white matter (estimate =-0.14, 95% CI: -0.27 to -0.01), and the corpus callosum (estimate =-0.09, 95% CI: -0.19 to 0.00) and amygdala (estimate =-0.05, 95% CI: -0.10 to 0.00). In contrast to the rapid brain growth observed earlier in development (i.e., T1 to T2), the IT-MTX + DEX group exhibited an attenuated increase in volume relative to the saline-treated group between T2 and T3.

Conclusions

The results demonstrate feasibility of modeling pediatric ALL treatment in a preclinical model and highlight the potential of using preclinical neuroimaging models to gain insight into brain development throughout survivorship.

Adaptive functioning and academic achievement in pediatric survivors of acute lymphoblastic leukemia: Associations with executive functioning, socioeconomic status, and academic support

OBJECTIVES

This study examines associations of functional outcomes (adaptive functioning and academic achievement) with executive functioning (EF), socioeconomic status (SES), and academic support in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

Fifty survivors of B-lineage ALL treated with chemotherapy-only (42% female, 76% NHW, ages 6-19) were evaluated on performance-based EF and academic achievement, and parent-rated EF and adaptive functioning. Area deprivation and child opportunity (i.e., SES) were extracted using census blocks and tracts. Academic support data were extracted from chart review.

RESULTS

Compared to population norms, pediatric ALL survivors demonstrated significantly lower overall adaptive skills and performance in word reading and math calculation (all p ≤ .011). Frequencies of impairment were significantly elevated on all adaptive scales and in math calculation compared to the population (all p ≤ .002). Parent-rated EF significantly predicted overall adaptive skills (p < .001), while performance-based EF significantly predicted word reading and math calculation (all p < .05). Adaptive functioning was not associated with neighborhood-specific variables or academic support. However, academic support predicted word reading (p < .001), while area deprivation and academic support predicted performance-based EF (all p ≤ .02).

CONCLUSIONS

Screening of functional outcomes, targeted intervention, and neuropsychological monitoring are necessary to support pediatric ALL survivors' neurocognitive and psychosocial development.

The association of environmental factors with neurocognitive outcomes in survivors of childhood acute lymphoblastic leukemia (ALL)

PURPOSE

To investigate the association of environmental factors, rehabilitation services during therapy and socioeconomic status (SES - insurance type), with neurocognitive outcomes at the end of therapy for survivors of childhood acute lymphoblastic leukemia (ALL).

METHODS

Survivors (n = 236) treated on the St. Jude Total Therapy Study 16 completed end of therapy testing with performance measures (IQ, attention, processing speed, fine motor skills, academics) and caregiver ratings (attention, executive function, adaptive skills). Environmental factors were abstracted from the medical record.

RESULTS

Distribution of sex (47.3% female, p = 0.399), treatment arm (45.5% low risk, 54.5% standard/high risk p = 0.929), insurance type (47.7% private, 52.3% public/none, p = 0.117), and mean age at diagnosis (7.7 vs. 6.8 years, p = 0.143) were similar for groups with (n = 110; 46.6%) and without (n = 126; 53.6%) rehabilitation services during therapy. Compared to those without rehabilitation, the rehabilitation group (n = 110; 46.4%) had more caregiver reported problems with attention (Z = -0.28 vs. 0.43, p = 0.022), executive function (Z = -0.50 vs. -0.08, p = 0.003), and adaptive skills (Z = -0.41 vs.-0.13, p = 0.031). Among the rehabilitation group, there was no difference in outcomes by insurance status. Among those without rehabilitation, those with public insurance had worse neurocognitive outcomes than those with private insurance in IQ (Z = -0.04 vs. -0.45, p = 0.0115), processing speed (Z = -0.10 vs. -0.75, p = 0.0030), reading (Z = 0.18 vs. -0.59, p < 0.0001), and math (Z = -0.04 vs. -0.50, p = 0.0021).

CONCLUSION

Participation in rehabilitation services during early intensive therapy is associated with end of therapy caregiver-reported neurocognitive outcomes in daily life.

Late-onset Cognitive Impairment and Modifiable Risk Factors in Adult Childhood Cancer Survivors

Importance

Long-term survivors of childhood cancer may be at elevated risk for new neurocognitive impairment and decline as they age into adulthood.

Objective

To determine whether aging adult childhood cancer survivors report more new-onset neurocognitive impairments compared with their siblings and to identify risk factors associated with such impairments.

Design, Setting, and Participants

Participants of this cohort study included adult survivors of childhood cancer from the Childhood Cancer Survivor Study and their siblings as a control group. The original cohort included survivors who received a diagnosis between January 1, 1970, and December 31, 1986, for whom longitudinal neurocognitive assessment was available. This study examined the prevalence of new-onset neurocognitive impairment between baseline (23.4 years after diagnosis) and follow-up (35.0 years after diagnosis). The analysis was performed from January 2021 to May 2022.

Exposures

Cancer treatment exposures were abstracted from medical records. Chronic health conditions were graded using Common Terminology Criteria for Adverse Events version 4.03.

Main Outcomes and Measures

The primary outcome was new-onset (present at follow-up, but not present at baseline) neurocognitive impairment (defined as a score in the worst 10% of the sibling cohort). Impairment was assessed using the Childhood Cancer Survivor Study Neurocognitive questionnaire. Relative risks (RRs) and 95% CIs were used to estimate associations of neurocognitive impairment with treatment and health behaviors and conditions using generalized linear models.

Results

The cohort comprised 2375 survivors (mean [SD] age at evaluation, 31.8 [7.5] years; 1298 women [54.6%]) of childhood cancer, including acute lymphoblastic leukemia (ALL; 1316 participants), central nervous system (CNS) tumors (488 participants), and Hodgkin lymphoma (HL; 571 participants). A total of 232 siblings (mean [SD] age at evaluation, 34.2 [8.4] years; 134 women [57.8%]) were included. Compared with siblings, a higher proportion of survivors with no impairment in memory at baseline had new-onset memory impairment at follow-up: siblings proportion, 7.8% (95% CI, 4.3%-11.4%); ALL survivors treated with chemotherapy only, 14.0% (95% CI, 10.7%-17.4%); ALL survivors treated with cranial radiation (CRT), 25.8% (95% CI, 22.6%-29.0%); CNS tumor survivors, 34.7% (95% CI, 30.0%-39.5%); and HL survivors, 16.6% (95% CI, 13.4%-19.8%). New-onset memory impairment was associated with CRT in CNS tumor survivors (RR, 1.97; 95% CI, 1.33-2.90) and alkylator chemotherapy greater than or equal to 8000 mg/m2 in ALL survivors treated without CRT (RR, 2.80; 95% CI, 1.28-6.12). Neurologic conditions mediated the impact of CRT on new-onset memory impairment in CNS survivors. Smoking, low educational attainment, and low physical activity were associated with elevated risk for new-onset memory impairment.

Conclusions and Relevance

These findings suggest that adult survivors of childhood cancer are at elevated risk for late-onset memory impairment related to modifiable risk factors identified early in survivorship.

[Recent research on cognitive impairment in children with acute lymphoblastic leukemia]

Acute lymphoblastic leukemia (ALL) is the most common malignant neoplastic disease in children. With the continuous improvement in diagnosis and treatment, there has been an increasing number of ALL children who achieve long-term survival after complete remission; however, a considerable proportion of these children have cognitive impairment, which has a serious adverse impact on their learning, employment, and social life. This article reviews the latest research on cognitive impairment in children with ALL from the aspects of the influencing factors, detection techniques, and prevention/treatment methods for cognitive impairment.

Leukoencephalopathy in children with acute lymphoblastic leukemia after chemotherapy: a retrospective monocenter study

Background

To investigate the clinical and neuroimaging characteristics of leukoencephalopathy among children with acute lymphoblastic leukemia (ALL), especially after chemotherapy.

Methods

Clinical data for 17 pediatric patients with leukoencephalopathy and 17 matched controls were retrospectively analyzed. All participants were children with ALL admitted to the Children's Hospital of Soochow University from May 2011 to April 2021. The data mainly consisted of general information, laboratory studies, and imaging diagnostic results.

Results

Overall, 94.12% of the patients experienced neurological symptoms. The most common symptoms were seizure (7/17, 41.18%), nausea (5/17, 29.41%), vomiting (5/17, 29.41%), paralysis (5/17, 29.41%), and numbness (4/17, 23.53%). On neuroimaging, multiple and irregular lesions were observed, distributed mainly in the periventricular area (9/17, 52.94%), parietal lobe (6/17, 35.29%), and basal ganglia (5/17, 29.41%). Moreover, there were significant differences in serum sodium (P=0.0001), C-reactive protein (P=0.0124) and blood pressure (P=0.0271) between patients with and without leukoencephalopathy. After aggressive treatment, the clinical symptoms (12/17, 70.59%) and imaging lesions (11/13, 84.62%) gradually improved in most patients.

Conclusions

Chemotherapy is an important risk factor related to leukoencephalopathy. Although the clinical symptoms of leukoencephalopathy vary widely, there is a high degree of consistency in its radiological features. Abnormal laboratory results may also help the identification of leukoencephalopathy. Early detection and treatment can improve brain development in the long term.

The Impact of Intensified CNS-Directed Therapy on Neurocognitive Outcomes in Survivors of Childhood Acute Lymphoblastic Leukemia Treated Without Cranial Irradiation

PURPOSE

Findings from St Jude Total Therapy Study 16 (Total 16) showed early intensification of triple intrathecal therapy (ITT) improved CNS disease control for children with newly diagnosed acute lymphoblastic leukemia (ALL) at the greatest risk of CNS relapse. We examined the impact of this treatment on end-of-therapy neurocognitive outcomes.

METHODS

Between 2007 and 2017, 400 (83.5%) of 479 eligible patients treated with Total 16 risk-directed chemotherapy completed protocol-directed neurocognitive testing at the end of therapy. Intensified ITT was defined as ≥ 21 cumulative doses for patients with low-risk ALL (n = 70/194) and ≥ 27 doses for those with standard-to-high risk ALL (n = 81/206).

RESULTS

Compared with age-normative expectations, the overall group had significantly lower estimated intelligence quotient (P < .0001), attention (P = .0051), working memory (P = .0001), processing speed (P = .0002), fine motor speed (P = .0001), and math (P = .0087). Caregiver ratings of patient functioning showed elevated risk for problems in attention (P = .0173), executive function (P = .0001), and adaptive skills (P = .0001). Among the low-risk treatment group, there were no significant differences between patients treated with or without intensified ITT (all P's >.10). Among patients with standard-to-high risk ALL, those treated with intensified ITT had poorer working memory (P = .0328) and fine motor speed (P = .0403), and elevated ratings of inattention (P = .0189) and executive dysfunction (P = .0245). In the standard-to-high risk group, females treated with intensified ITT had lower working memory scores. Public insurance status was associated with worse neurocognitive outcomes in both treatment groups.

CONCLUSION

Standard-to-high risk patients treated with intensified ITT are at moderately increased risk for neurocognitive problems. The findings suggest a threshold effect for ITT exposure, which can inform the design of future clinical trials and approaches to neurocognitive monitoring and intervention.

Comparison of Neurocognitive Functioning and Fine Motor Skills in Pediatric Cancer Survivors and Healthy Children

Background: The late treatment outcomes of pediatric brain tumors and of hematopoietic and lymphoid tissue tumors are an important focus of both rehabilitation and research. Neurocognitive and motor disorders induce further learning problems impeding social-emotional adaptation throughout a whole lifespan. Core deficits in short-term and working memory, visuospatial constructional ability, verbal fluency, and fine motor skills underlie distorted intellectual and academic achievement. This study aimed to assess the individual differences in cognitive ability and fine motor skills of pediatric tumor survivors and the age-matched healthy controls. Methods: A total of 504 tumor survivors after treatment and 646 age-matched healthy controls underwent neurocognitive and fine motor assessments. Findings: The group of tumor survivors scored significantly worse in both neurocognitive and fine motor skill in compared with the healthy control group. The pediatric brain tumor survivors (PBT group) performed worse in cognitive (p < 0.001 for verbal fluency and p < 0.001 for visuospatial constructional ability) and motor tests (p < 0.001) compared to the healthy controls. Hematopoietic and Lymphoid Tissues tumors survivors (THL group) performed worse in verbal fluency (p < 0.01) and visuospatial constructional test (p < 0.001) compared to the control group. Furthermore, the PBT group had worse results in visuospatial constructional ability (p < 0.05) and fine motor (p < 0.001) ability than the THL group. Significant differences between females and males were found in fine motor test performance in the PBT group (p < 0.05), as well as in verbal fluency (p < 0.01) and visuospatial constructional ability (p < 0.01) in the control group. Neurocognitive and fine motor skill characteristics in the THL group did not correlate with age.

Is Brain Network Efficiency Reduced in Young Survivors of Acute Lymphoblastic Leukemia?-Evidence from Individual-Based Morphological Brain Network Analysis

Altered cerebral structure and function have been observed in young survivors of acute lymphoblastic leukemia (ALL). However, the topological organization of the morphological brain networks (MBNs) has not yet been investigated at the individual level. Twenty-three young survivors of ALL and twenty healthy controls (HCs) were recruited and underwent T1-weighted magnetic resonance imaging (MRI) scanning. After preprocessing and segmentation, individual-based MBNs were constructed based on the morphological similarity of gray matter using the combined Euclidean distance. Young survivors showed a significantly lower global clustering coefficient (p = 0.008) and local efficiency (p = 0.035) compared with HCs. In addition, ALL survivors exhibited bidirectional alterations (decreases and increases) in nodal centrality and efficiency around the Rolandic operculum and posterior occipital lobe (p < 0.05, false discovery rate (FDR) corrected). Altered nodal topological efficiencies were associated with off-therapy duration and verbal memory capacity in the digit span test (p < 0.05, FDR corrected). Network-based statistical analysis revealed decreased morphological connections mainly in the pallidum subnetwork, which was negatively correlated with off-therapy durations (p < 0.05). Overall, the topological organization of the individual-based MBNs was disrupted in the young survivors of ALL, which may play a crucial role in executive efficiency deficits.

Brain morphological alterations and their correlation to tumor differentiation and duration in patients with lung cancer after platinum chemotherapy

OBJECTIVE

Chemotherapy-related brain impairments and changes can occur in patients with lung cancer after platinum chemotherapy and have a substantial impact on survivors' quality of life. Therefore, it is necessary to understand the brain neuropathological alterations and response mechanisms to provide a theoretical basis for rehabilitation strategies. This study aimed to investigate the related brain morphological changes and clarified their correlation with clinical and pathological indicators in patients with lung cancer after platinum chemotherapy.

METHODS

Overall, 28 patients with chemotherapy, 56 patients without chemotherapy, and 41 healthy controls were categorized in three groups, matched for age, sex, and years of education, and included in the cross-sectional comparison of brain volume and cortical thickness. 14 matched patients before and after chemotherapy were subjected to paired comparison for longitudinal observation of brain morphological changes. Three-dimensional T1-weighted images were acquired from all participants, and quantitative parameters were calculated using the formula of the change from baseline. Correlation analysis was performed to evaluate the relationship between abnormal morphological indices and clinical information of patients.

RESULTS

Brain regions with volume differences among the three groups were mainly distributed in frontal lobe and limbic cortex. Additionally, significant differences in cerebrospinal fluid were observed in most ventricles, and the main brain regions with cortical thickness differences were the gyrus rectus and medial frontal cortex of the frontal lobe, transverse temporal gyrus of the temporal lobe, insular cortex, anterior insula, and posterior insula of the insular cortex. According to the paired comparison, decreased brain volumes in the patients after chemotherapy appeared in some regions of the frontal, parietal, temporal, and occipital lobes; limbic cortex; insular cortex; and lobules VI-X and decreased cortical thickness in the patients after chemotherapy was found in the frontal, temporal, limbic, and insular cortexes. In the correlation analysis, only the differentiation degree of the tumor and duration after chemotherapy were significantly correlated with imaging indices in the abnormal brain regions.

CONCLUSIONS

Our findings illustrate the platinum-related brain reactivity morphological alterations which provide more insights into the neuropathological mechanisms of patients with lung cancer after platinum chemotherapy and empirical support for the details of brain injury related to cancer and chemotherapy.

Changes in Brain Functional and Effective Connectivity After Treatment for Breast Cancer and Implications for Intervention Targets

Background: Patients with breast cancer frequently report cognitive impairment both during and after completion of therapy. Evidence suggests that cancer-related cognitive impairments are related to widespread neural network dysfunction. The default mode network (DMN) is a large conserved network that plays a critical role in integrating the functions of various neural systems. Disruption of the network may play a key role in the development of cognitive impairment. Methods: We compared neuroimaging and neurocognitive data from 43 newly diagnosed primary breast cancer patients (mean age = 48, standard deviation [SD] = 8.9 years) and 50 frequency-matched healthy female controls (mean age = 50, SD = 10 years) before treatment and 1 year after treatment completion. Functional and effective connectivity measures of the DMN were obtained using graph theory and Bayesian network analysis methods, respectively. Results: Compared with healthy females, the breast cancer group displayed higher global efficiency and path length post-treatment (p < 0.03, corrected). Breast cancer survivors showed significantly lower performance on measures of verbal memory, attention, and verbal fluency (p < 0.05) at both time points. Within the DMN, local brain network organization, as measured by edge-betweenness centralities, was significantly altered in the breast cancer group compared with controls at both time points (p < 0.0001, corrected), with several connections showing a significant group-by-time effect (p < 0.003, corrected). Effective connectivity demonstrated significantly altered patterns of neuronal coupling in patients with breast cancer (p < 0.05). Significant correlations were seen between hormone blockade therapy, radiation therapy, chemotherapy cycles, memory, and verbal fluency test and edge-betweenness centralities. Discussion: This pattern of altered network organization in the default mode is believed to result in reduced network efficiency and disrupted communication. Subregions of the DMN, the orbital prefrontal cortex and posterior memory network, appear to be at the center of this disruption and this could inform future interventions. Impact statement This prospective study is the first to investigate how post-treatment changes in functional and effective connectivity in the regions of default mode network are related to cancer therapy and measures of memory and verbal learning in breast cancer patients. We demonstrate that the interactions between treatment, brain connectivity, and neurocognitive outcomes coalesce around a subgroup of brain structures in the orbital frontal and parietal lobe. This would suggest that interventions that target these regions may improve neurocognitive outcomes in breast cancer survivors.

Targeting the Meningeal Compartment to Resolve Chemobrain and Neuropathy via Nasal Delivery of Functionalized Mitochondria

Cognitive deficits (chemobrain) and peripheral neuropathy occur in ∼75% of patients treated for cancer with chemotherapy and persist long-term in >30% of survivors. Without preventive or curative interventions and with increasing survivorship rates, the population debilitated by these neurotoxicities is rising. Platinum-based chemotherapeutics, including cisplatin, induce neuronal mitochondrial defects leading to chemobrain and neuropathic pain. This study investigates the capacity of nasally administered mesenchymal stem cell-derived mitochondria coated with dextran-triphenylphosphonium polymer (coated mitochondria) to reverse these neurotoxicities. Nasally administered coated mitochondria are rapidly detectable in macrophages in the brain meninges but do not reach the brain parenchyma. The coated mitochondria change expression of >2400 genes regulating immune, neuronal, endocrine and vascular pathways in the meninges of mice treated with cisplatin. Nasal administration of coated mitochondria reverses cisplatin-induced cognitive deficits and resolves neuropathic pain at a >55-times lower dose compared to uncoated mitochondria. Reversal of these neuropathologies is associated with resolution of cisplatin-induced deficits in myelination, synaptosomal mitochondrial integrity and neurogenesis. These findings demonstrate that nasally administered coated mitochondria promote resolution of chemobrain and peripheral neuropathy, thereby identifying a novel facile strategy for clinical application of mitochondrial donation and treating central and peripheral nervous system pathologies by targeting the brain meninges.

Default-Mode Network Connectivity Changes Correlate with Attention Deficits in ALL Long-Term Survivors Treated with Radio- and/or Chemotherapy

Simple Summary

Both chemotherapy and radiotherapy play a role in the neurocognitive impairment of long-term survivors from acute lymphoblastic leukemia, but it is unknown if similar mechanisms are involved. We assessed neurocognitive alterations, brain tissue volumes, and functional connectivity of the main hubs of the default-mode network, in 13 patients treated with chemotherapy and radiotherapy (Group A) and in 13 treated with chemotherapy only (Group B). Correlations with neuropsychological scores, independent of group, were assessed for regions that showed significant differences between the two groups at neuroimaging. Compared to Group B, Group A performed significantly worse at the digit span and digit symbol tests and showed increased functional connectivity between the medial prefrontal cortex and the rolandic operculi, along with the absence of differences in regional brain tissue volumes. Functional connectivity in these regions correlated inversely with speed of processing in both groups, suggesting that similar mechanisms may be involved in the neurocognitive deficits in both groups.

Abstract

Whether chemotherapy (ChT) and radiotherapy (RT) determine neurocognitive impairment in acute lymphoblastic leukemia long-term survivors (ALL LTSs) through similar mechanisms affecting the same brain regions is still unknown. We compared neurocognitive alterations, regional brain tissue volumes (by voxel-based morphometry), and functional connectivity of the main default-mode network hubs (by seed-based analysis of resting state functional MRI data), in 13 ALL LTSs treated with RT and ChT (Group A) and 13 treated with ChT only (Group B). Group A performed significantly worse than Group B at the digit span and digit symbol tests (p = 0.023 and 0.013, respectively). Increased connectivity between the medial prefrontal cortex (the main anterior hub of the default-mode network) and the rolandic operculi was present in Group A compared to Group B, along with the absence of significant differences in regional brain tissue volumes. In these regions, the functional connectivity correlated inversely with the speed of processing scores, independent of treatment group. These results suggest that similar mechanisms may be involved in the neurocognitive deficits in ALL LTS patients, regardless of the treatment group. Further studies are needed to clarify whether these changes represent a direct expression of the mechanisms underlying the cognitive deficits or ineffective compensatory phenomena.

Lower Socioeconomic Position Is Associated with Greater Activity in and Integration within an Allostatic-Interoceptive Brain Network in Response to Affective Stimuli

Socioeconomic inequities shape physical health and emotional well-being. As such, recent work has examined the neural mechanisms through which socioeconomic position (SEP) may influence health. However, there remain critical gaps in knowledge regarding the relationships between SEP and brain function. These gaps include a lack of research on: (1) the association between SEP and brain functioning in later life, (2) relationships between SEP and functioning of the whole brain beyond specific regions of interest, and (3) how neural responses to positive affective stimuli differ by SEP. The current study addressed these gaps by examining the association between SEP (i.e., education, income) and neural responses to affective stimuli among 122 mid- to late-life adults. During MRI scanning, participants viewed 30 positive, 30 negative, and 30 neutral images; activation and network connectivity analyses explored associations between SEP and neural responses to these affective stimuli. Analyses revealed that those with lower SEP showed greater neural activity to both positive and negative images in regions within the allostatic-interoceptive network, a system of regions implicated in representing and regulating physiological states of the body and the external environment. There were no positive associations between SEP and neural responses to negative or positive images. In addition, graph-theory network analyses showed that individuals with lower SEP demonstrated greater global efficiency within the allostatic-interoceptive network and executive control network, across all task conditions. The findings suggest that lower SEP is associated with enhanced neural sensitivity to affective cues that may be metabolically costly to maintain over time and suggest a mechanism by which SEP might get "under the skull" to influence mental and physical well-being.

Cognitive Rehabilitation for Neurocognitive Late Effects in Adult Survivors of Childhood Acute Lymphoblastic Leukemia: A Feasibility and Case-Series Study

Neurocognitive late effects following the diagnosis and treatment of childhood acute lymphoblastic leukemia (ALL) commonly include impaired executive functions (EFs), with negative consequences for one's health-related quality of life and mental health. However, interventions for EF impairments are scarce. Thus, the aims of this study were to (1) explore the feasibility and acceptability of the cognitive rehabilitation program Goal Management Training (GMT) and (2) examine whether GMT is associated with positive outcomes across cases of ALL survivors with EF complaints. Four participants (median age 31.5 years) underwent nine GMT modules in a total of five group sessions. Rehabilitation was focused on compensatory strategies to improve real-life EFs. Participants were evaluated at 2-week and 6-month follow-ups. Evaluation of feasibility and acceptability included adherence, a semi structured interview, self-reports, and safety. Additionally, therapists' experience with implementation was evaluated. Outcome measures included self-reports and neurocognitive tests of attention, EF, and processing speed. All participants completed GMT and rated the intervention as useful, suitable, and satisfactory. The reliable change index showed improved daily life EFs (two participants) and neurocognitive performance (three participants) at 6-month follow-up. Additionally, all participants improved on a "real-life" task involving EF. A future randomized controlled trial is recommended.

Structural and Functional Brain Imaging in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia Treated With Chemotherapy: A Systematic Review

Background

The effect of chemotherapy on brain development in long-term survivors of pediatric acute lymphoblastic leukemia (ALL) was systematically reviewed.

Methods

A systematic search of Pubmed, Scopus, and PsycINFO databases was conducted to identify articles published between January 2000 and February 2020 that implemented magnetic resonance imaging to assess brain structure and function in pediatric ALL survivors (diagnosed younger than 21 years of age). The review included articles that were published on children diagnosed with ALL between 0 and 21 years of age and treated with chemotherapy-only protocols. Articles meeting the inclusion criteria described survivors on average of 5 years or more from diagnosis and were peer-reviewed articles and original studies.

Results

The search yielded 1975 articles with 23 articles meeting inclusion criteria. The review revealed that survivors had statistically significant alterations in brain anatomy, most commonly a smaller hippocampus and impaired microstructural white matter integrity in frontal brain regions. Survivors also had impaired brain function including lower brain network efficiency and altered resting state connectivity. Survivors also displayed widespread reductions in brain activation (ie, frontal, temporal, parietal brain regions) during cognitive tasks.

Conclusion

Although the neurotoxic effects of cancer treatment are reduced in the absence of cranial radiation, survivors treated on chemotherapy-only protocols still display long-term alterations in brain structure and function, which contribute to lifelong neurocognitive late effects.

European Society for Paediatric Oncology (SIOPE) MRI guidelines for imaging patients with central nervous system tumours

INTRODUCTION

Standardisation of imaging acquisition is essential in facilitating multicentre studies related to childhood CNS tumours. It is important to ensure that the imaging protocol can be adopted by centres with varying imaging capabilities without compromising image quality.

MATERIALS AND METHOD

An imaging protocol has been developed by the Brain Tumour Imaging Working Group of the European Society for Paediatric Oncology (SIOPE) based on consensus among its members, which consists of neuroradiologists, imaging scientists and paediatric neuro-oncologists. This protocol has been developed to facilitate SIOPE led studies and regularly reviewed by the imaging working group.

RESULTS

The protocol consists of essential MRI sequences with imaging parameters for 1.5 and 3 Tesla MRI scanners and a set of optional sequences that can be used in appropriate clinical settings. The protocol also provides guidelines for early post-operative imaging and surveillance imaging. The complementary use of multimodal advanced MRI including diffusion tensor imaging (DTI), MR spectroscopy and perfusion imaging is encouraged, and optional guidance is provided in this publication.

CONCLUSION

The SIOPE brain tumour imaging protocol will enable consistent imaging across multiple centres involved in paediatric CNS tumour studies.

Cortical Morphometry and Its Relationship with Cognitive Functions in Children after non-CNS Cancer

Background: Childhood cancer survivors (Ccs) are at risk for cognitive late-effects, which might result from cortical alterations, even if cancer does not affect the brain. The study aimed to examine gray and white matter volume and its relationship to cognition. Methods: Forty-three Ccs of non-central nervous system cancers and 43 healthy controls, aged 7-16 years, were examined. Cognitive functions and fine motor coordination were assessed and T1-weighted images were collected for voxel-based morphometry. Results: Executive functions (p = .024, d = .31) were poorer in Ccs than controls, however still within the normal range. The volume of the amygdala (p = .011, ŋ² = .117) and the striatum (p = .03, ŋ² = .102) was reduced in Ccs. No significant structure-function correlations were found, neither in patients nor controls. Conclusion: Non-CNS childhood cancer and its treatment impacts on brain structures relevant to emotion processing.

The association of genetic polymorphisms with neuroconnectivity in breast cancer patients

Genetic polymorphisms in select genes, including APOE (apolipoprotein E), COMT (Catechol-O-Methyltransferase), MDR1 (multi-drug resistance 1), BDNF (brain derived neurotrophic factor), and GST (glutathione-S-transferase), have been associated with vulnerability to cognitive impairment. In this study, we evaluated the relationship of these genetic variants to measures of brain health in patients with breast cancer, including neurocognitive testing and functional connectome analysis. Women with breast cancer (n = 83) and female healthy controls (n = 53) were evaluated. They underwent resting-state functional MRI scans and neurocognitive testing. Polymerase chain reaction (PCR) was performed on saliva samples to identify single nucleotide polymorphisms (SNPs) in candidate genes: APOE, COMT, MDR1, BDNF, and GST. Breast cancer patients treated with chemotherapy had slower processing speed (p = 0.04) and poorer reported executive function (p < 0.0001) than healthy controls. Those chemotherapy-treated patients that were APOE e4 carriers had significantly slower processing speed. A greater number of risk-related alleles was associated with poorer connectivity in the regions of the left cuneus and left calcarine. While breast cancer patients that are APOE e4 carriers may have a select vulnerability to processing speed impairments, other risk-related alleles were not found to influence cognitive test performance in this population. Conversely, regions of impaired functional connectivity appeared to be related to risk-related genetic polymorphisms in breast cancer patients. This suggests that a cancer patient’s SNPs in candidate genes may influence the risk of neurotoxicity. Further study evaluating the impact of genotype on biomarkers of brain health in cancer survivors is warranted.

A Unifying Theory for Autism: The Pathogenetic Triad as a Theoretical Framework

This paper presents a unifying theory for autism by applying the framework of a pathogenetic triad to the scientific literature. It proposes a deconstruction of autism into three contributing features (an autistic personality dimension, cognitive compensation, and neuropathological risk factors), and delineates how they interact to cause a maladaptive behavioral phenotype that may require a clinical diagnosis. The autistic personality represents a common core condition, which induces a set of behavioral issues when pronounced. These issues are compensated for by cognitive mechanisms, allowing the individual to remain adaptive and functional. Risk factors, both exogenous and endogenous ones, show pathophysiological convergence through their negative effects on neurodevelopment. This secondarily affects cognitive compensation, which disinhibits a maladaptive behavioral phenotype. The triad is operationalized and methods for quantification are presented. With respect to the breadth of findings in the literature that it can incorporate, it is the most comprehensive model yet for autism. Its main implications are that (1) it presents the broader autism phenotype as a non-pathological core personality domain, which is shared across the population and uncoupled from associated features such as low cognitive ability and immune dysfunction, (2) it proposes that common genetic variants underly the personality domain, and that rare variants act as risk factors through negative effects on neurodevelopment, (3) it outlines a common pathophysiological mechanism, through inhibition of neurodevelopment and cognitive dysfunction, by which a wide range of endogenous and exogenous risk factors lead to autism, and (4) it suggests that contributing risk factors, and findings of immune and autonomic dysfunction are clinically ascertained rather than part of the core autism construct.

Childhood Neurotoxicity and Brain Resilience to Adverse Events during Adulthood

OBJECTIVE

This study used childhood cancer survivors as a novel model to study whether children who experience central nervous system (CNS) injury are at higher risk for neurocognitive impairment associated with subsequent late onset chronic health conditions (CHCs).

METHODS

Adult survivors of childhood cancer (n = 2,859, ≥10 years from diagnosis, ≥18 years old) completed a comprehensive neurocognitive battery and clinical examination. Neurocognitive impairment was defined as age-adjusted z score < 10th percentile. Participants impaired on ≥3 tests had global impairment. CHCs were graded using the Common Terminology Criteria for Adverse Events v4.3 (grade 1, mild; 2, moderate; 3, severe/disabling; 4, life-threatening) and were combined into a severity/burden score by frequency and grade (none/low, medium, high, and very high). A total of 1,598 survivors received CNS-directed therapy including cranial radiation, intrathecal methotrexate, or neurosurgery. Logistic regression estimated the odds of neurocognitive impairment associated with severity/burden score and grade 2 to 4 conditions, stratified by CNS treatment.

RESULTS

CNS-treated survivors performed worse than non-CNS-treated survivors on all neurocognitive tests and were more likely to have global neurocognitive impairment (46.9% vs 35.3%, p < 0.001). After adjusting for demographic and treatment factors, there was a dose-response association between severity/burden score and global neurocognitive impairment, but only among CNS-treated survivors (high odds ratio [OR] = 2.24, 95% confidence interval [CI] = 1.42-3.53; very high OR = 4.07, 95% CI = 2.30-7.17). Cardiovascular and pulmonary conditions were associated with processing speed, executive function, and memory impairments in CNS-treated but not non-CNS-treated survivors who were impacted by neurologic conditions.

INTERPRETATION

Reduced cognitive/brain reserve associated with CNS-directed therapy during childhood may make survivors vulnerable to adverse cognitive effects of cardiopulmonary conditions during adulthood. ANN NEUROL 2021;89:534-545.

Sex Differences in the Association between Household Income and Children's Executive Function

The study aimed to investigate sex differences in the boosting effects of household income on children's executive function in the US. This is a cross-sectional study using data from Wave 1 of the Adolescent Brain Cognitive Development (ABCD) study. Wave 1 ABCD included 8608 American children between ages 9 and 10 years old. The independent variable was household income. The primary outcome was executive function measured by the stop-signal task. Overall, high household income was associated with higher levels of executive function in the children. Sex showed a statistically significant interaction with household income on children's executive function, indicating a stronger effect of high household income for female compared to male children. Household income is a more salient determinant of executive function for female compared to male American children. Low-income female children remain at the highest risk regarding poor executive function.

Connectivity of the Cerebello-Thalamo-Cortical Pathway in Survivors of Childhood Leukemia Treated With Chemotherapy Only

IMPORTANCE

Treatment with contemporary chemotherapy-only protocols is associated with risk for neurocognitive impairment among survivors of childhood acute lymphoblastic leukemia (ALL).

OBJECTIVE

To determine whether concurrent use of methotrexate and glucocorticoids is associated with interference with the antioxidant system of the brain and damage and disruption of glucocorticoid-sensitive regions of the cerebello-thalamo-cortical network.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted from December 2016 to July 2019 in a single pediatric cancer tertiary care center. Participants included survivors of childhood ALL who were more than 5 years from cancer diagnosis, age 8 years or older, and treated on an institutional chemotherapy-only protocol. Age-matched community members were recruited as a control group. Data were analyzed from August 2017 to August 2020.

EXPOSURE

ALL treatment using chemotherapy-only protocols.

MAIN OUTCOMES AND MEASURES

This study compared brain volumes between survivors and individuals in a community control group and examined associations among survivors of methotrexate and dexamethasone exposure with neurocognitive outcomes. Functional and effective connectivity measures were compared between survivors with and without cognitive impairment. The Rey-Osterrieth complex figure test, a neurocognitive evaluation in which individuals are asked to copy a figure and then draw the figure from memory, was scored according to published guidelines and transformed into age-adjusted z scores based on nationally representative reference data and used to measure organization and planning deficits. β values for neurocognitive tests represented the amount of change in cerebellar volume or chemotherapy exposure associated with 1 SD change in neurocognitive outcome by z score (mm3/1 SD in z score for cerebellum, mm3/[g×hr/L] for dexamethasone and methotrexate AUC, and mm3/intrathecal count for total intrathecal count).

RESULTS

Among 302 eligible individuals, 218 (72%) participated in the study and 176 (58%) had usable magnetic resonance imaging (MRI) results. Among these, 89 (51%) were female participants and the mean (range) age was 6.8 (1-18) years at diagnosis and 14.5 (8-27) years at evaluation. Of 100 community individuals recruited as the control group, 82 had usable MRI results; among these, 35 (43%) were female individuals and the mean (range) age was 13.8 (8-26) years at evaluation. There was no significant difference in total brain volume between survivors and individuals in the control group. Survivors of both sexes showed decreased mean (SD) cerebellar volumes compared with the control population (female: 70 568 [6465] mm3 vs 75 134 [6780] mm3; P < .001; male: 77 335 [6210] mm3 vs 79 020 [7420] mm3; P < .001). In female survivors, decreased cerebellar volume was associated with worse performance in Rey-Osterrieth complex figure test (left cerebellum: β = 55.54; SE = 25.55; P = .03; right cerebellum: β = 52.57; SE = 25.50; P = .04) and poorer dominant-hand motor processing speed (ie, grooved pegboard performance) (left cerebellum: β = 82.71; SE = 31.04; P = .009; right cerebellum: β = 91.06; SE = 30.72; P = .004). In female survivors, increased number of intrathecal treatments (ie, number of separate injections) was also associated with Worse Rey-Osterrieth test performance (β = -0.154; SE = 0.063; P = .02), as was increased dexamethasone exposure (β = -0.0014; SE = 0.0005; P = .01). Executive dysfunction was correlated with increased global efficiency between smaller brain regions (Pearson r = -0.24; P = .01) compared with individuals without dysfunction. Anatomical connectivity showed differences between impaired and nonimpaired survivors. Analysis of variance of effective-connectivity weights identified a significant interaction association (F = 3.99; P = .02) among the direction and strength of connectivity between the cerebellum and DLPFC, female sex, and executive dysfunction. Finally, no effective connectivity was found between the precuneus and DLPFC in female survivors with executive dysfunction.

CONCLUSIONS AND RELEVANCE

These findings suggest that dexamethasone exposure was associated with smaller cerebello-thalamo-cortical regions in survivors of ALL and that disruption of effective connectivity was associated with impairment of executive function in female survivors.

Altered Functional Connectivity Density in Young Survivors of Acute Lymphoblastic Leukemia Using Resting-State fMRI

Objective

Using functional connectivity density (FCD) mapping measured by resting-state functional magnetic resonance imaging (rs-fMRI), an ultrafast data-driven graph theory approach, we attempted to study the abnormalities in neural activity of young survivors of acute lymphoblastic leukemia (ALL) and to explore the neuropathological evidence of chemotherapy-related cognitive impairment of patients.

Methods

Twenty young survivors of ALL and 18 well-matched healthy controls (HCs) were recruited in this study. All ALL patients and healthy controls underwent rs-fMRI scans and completed neurocognitive testing. The between-group differences in short-range and long-range FCD were calculated by the option of degree centrality (DC) in MATLAB software after preprocessing. The correlations between the FCD value and each of the neurocognitive outcomes were analyzed in the ALL patients.

Results

The group-averaged FCD maps showed similar spatial patterns between the two groups. Compared with the HCs, ALL patients showed decreased long-range FCD in regions of the bilateral lingual gyrus, cingulate cortex, hippocampal gyrus, and right calcarine fissure. Simultaneously, decreased regions in the short-range FCD map were the bilateral lingual gyrus, cingulate cortex, parahippocampal gyrus and right calcarine fissure. Increased functional connectivity (FC) was observed between the region with decreased long-range FCD and the posterior cerebellar lobe, and decreased FC was observed between the region and the middle occipital gyrus, cuneus and lingual gyrus. Thus, there existed no brain areas with increased FCD. The decreased short-range FCD value of ALL patients was positively correlated with the score on the Digit Span Test (Forward), and the increased FC value was negatively correlated with the score on the Trail Making Test part A.

Conclusion

Our results suggest the altered functional connectivity of young survivors of ALL in the posterior region of the brain and posterior lobe of the cerebellum. Alterations in spontaneous neuronal activity seem to parallel the neurocognitive testing, which indicates that the rs-fMRI could be used as a neuroimaging marker for neurological impairment in ALL patients.

Functional connectome biotypes of chemotherapy-related cognitive impairment

PURPOSE

Cancer-related cognitive impairment (CRCI) is a common neurotoxicity among patients with breast and other cancers. Neuroimaging studies have demonstrated measurable biomarkers of CRCI but have largely neglected the potential heterogeneity of the syndrome.

METHODS

We used retrospective functional MRI data from 80 chemotherapy-treated breast cancer survivors to examine neurophysiologic subtypes or "biotypes" of CRCI. The breast cancer group consisted of training (N = 57) and validation (N = 23) samples.

RESULTS

An unsupervised clustering approach using connectomes from the training sample identified three distinct biotypes. Cognitive performance (p < 0.05, corrected) and regional connectome organization (p < 0.001, corrected) differed significantly between the biotypes and also from 103 healthy female controls. We then built a random forest classifier using connectome features to distinguish between the biotypes (accuracy = 91%) and applied this to the validation sample to predict biotype assignment. Cognitive performance (p < 0.05, corrected) and regional connectome organization (p < 0.005, corrected) differed significantly between the predicted biotypes and healthy controls. Biotypes were also characterized by divergent clinical and demographic factors as well as patient reported outcomes.

CONCLUSIONS

Neurophysiologic biotypes may help characterize the heterogeneity associated with CRCI in a data-driven manner based on neuroimaging biomarkers.

IMPLICATIONS FOR CANCER SURVIVORS

Our novel findings provide a foundation for detecting potential risk and resilience factors that warrant further study. With further investigation, biotypes might be used to personalize assessments of and interventions for CRCI.

Assessment of Executive Functions after Treatment of Childhood Acute Lymphoid Leukemia: a Systematic Review

Individuals treated for childhood acute lymphoblastic leukemia (ALL) have a high survival rate. This fact, however, may lead to neurocognitive impairments in survivors, as shown in some studies. The prefrontal cortex and executive functions seem to be particularly vulnerable due to the late maturation in the development process. Executive impairments have been associated with poorer quality of life in childhood cancer survivors. A systematic review was carried out with studies that assessed executive functions in childhood ALL survivors.\ Studies were collected from five electronic databases: MEDLINE (PubMed); PsycInfo; WebOfScience; LILACS and IBECS. Eighty-four studies were retrieved from the database search, of which 50 were read in full and 26 met the inclusion criteria. The studies were heterogeneous as to the instruments used to assess executive function, the skills assessed and the comparison methods. Despite some discrepancies, ALL survivors seem to exhibit poorer executive functioning than typical controls, but this result did not hold true when subjects were compared to normative mean. Changes in brain structure and dynamics resulting from the disease itself, the toxicity of the treatment and difficulties in coping with the stress during treatment may be related to executive impairments in ALL survivors. Discussion proposed standardized methods and measures for assessing executive functioning in children during and after ALL treatment.

Beyond Risk-Based Stratification: Impacts of Processing Speed and Executive Function on Adaptive Skills in Adolescent and Young Adult Cancer Survivors

Purpose: The number of adolescent and young adult (AYA) survivors of childhood cancer is increasing, and the impacts of therapy on their daily lives are not well understood. Adaptive functions are required for age-appropriate interactions and day to day functioning, but are reduced in AYA survivors. Work in other pediatric populations suggests that additional neurocognitive skills may influence adaptive function and, thus, quality of life and personal attainment of AYA cancer survivors. Methods: Retrospective medical records review examined neurocognitive data from 139 AYA survivors. Hierarchical linear regression examined age at diagnosis, use of central nervous system (CNS) radiation, verbal intelligence, processing speed, and executive function as predictors of adaptive functioning domains. Results: AYA survivors exhibited weaknesses in all domains of adaptive functioning compared to normative reference values (Cohen's d = 0.660-0.864), as well as in processing speed (Cohen's d = 0.791) and metacognitive executive functioning (Cohen's d = 0.817). Processing speed and executive function provided substantial improvements in prediction of adaptive functioning beyond that of age at diagnosis and use of CNS-directed radiation therapy. Taken together these variables explained 37.1% of variability in adaptive conceptual skills, 26.1% in adaptive social skills, and 27.1% of adaptive practical skills. Conclusions: Intelligence, processing speed, and executive function significantly contribute to adaptive function scores in AYA cancer survivors and impact domains that are important to self-sufficiency and quality of life. Attention to neurocognitive function in all AYA cancer survivors is recommended in addition to referral for neuropsychological evaluation and tailoring interventions to address executive and adaptive functioning.

Neurodevelopmental Consequences of Pediatric Cancer and Its Treatment: The Role of Sleep

Cognitive impairment is frequent in pediatric cancer, and behavioral and psychological disturbances often also affect children who have survived cancer problems. Furthermore, pediatric tumors are also often associated with sleep disorders. The interrelationship between sleep disorders, neurodevelopmental disorders and pediatric cancer, however, is still largely unexplored. In this narrative review we approach this important aspect by first considering studies on pediatric cancer as a possible cause of neurodevelopmental disorders and then describing pediatric cancer occurring as a comorbid condition in children with neurodevelopmental disorders. Finally, we discuss the role of sleep disorders in children with cancer and neurodevelopmental disorders. Even if the specific literature approaching directly the topic of the role of sleep in the complex relationship between pediatric cancer and neurodevelopmental disorders was found to be scarce, the available evidence supports the idea that in-depth knowledge and correct management of sleep disorders can definitely improve the health and quality of life of children with cancer and of their families.